Tag: Frost

Frosty to Start the Week

Brad Leave a comment

We’ll be in for a couple of chilly, perhaps you could even say frosty, days to start this week. Cool daytime highs and sub-zero nighttime lows are on tap.

GEM-REG 3hr. Precipitation Accumulation

Some light lake effect showers (shown in blue) are expected to develop on Monday as cold air flows over the relatively warm lakes winnipeg and manitoba.

After a rather chilly Monday morning, temperatures won’t make a dramatic recovery for the afternoon. Daytime highs on the first day of the week are expected to barely make the double digits in most areas, with highs generally in the 9-12C range expected. A breezy north wind and perhaps a couple of lake-effect showers won’t make the day any more pleasant. Tuesday night should be another cool one in Southern Manitoba. However, it appears frost will be isolated to areas around and east of the Red River Valley as some warmer air moving in from the west will keep temperatures above zero overnight in Western Manitoba. Daytime highs on Tuesday will be an improvement from Monday, though except for South-Western Manitoba where 20C values are expected, temperatures will generally remain stuck in the mid teens.

Yet another cold front will swing through overnight Tuesday into Wednesday ushering in another cool airmass to end the week. It appears high temperatures will be relegated to the teens from Wednesday through Friday. There appears to be slim odds of any significant precipitation this week, though we may at least get some measureable rain later in the week as a few strong impulses rotate through the region.

NAEFS Ensemble 8-14 day outlook

The NAEFS ensemble doesn’t give a strong indication of what type of weather we’ll see moving forward…

At this point the long range forecast looks fairly status quo. We’ll see some cooler than normal days and some warmer than normal days, but in general the pattern for the next week or two generally looks to be near normal on average. However, there will certainly be a fall feel to the air as nighttime temperatures regular drop down to the freezing mark and daytime highs stay close to the average high for mid-September of 18C.

Cool, Wet Weather For The Weekend

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Winnipeggers: get ready for a shock. The next few days are going to be startling chilly with daytime highs over 10°C below normal and overnight lows over 5°C below normal. Another thing that will be noticably absent other than warmth? The sun will make only a few rare appearances over the next several days as another system pushes into Southern Manitoba, bringing another round of rain and thunderstorms to the Red River Valley.

850mb Temperatures valid 00Z Friday

850mb temperatures vaild at 00Z Sat. May 26 (Friday evening). An elongated cold trough is sweeping across Southern Manitoba, bringing 850mb temperatures in the -2 to -5°C range.

This cool weather has brought late-season (or is it early-season now?) snow to several communities over Western Manitoba including The Pas, Flin Flon and higher elevations over SW Manitoba (Duck Mountain & Riding Mountain areas). A few leftover flurries will scoot across the Interlake this morning and exit out of the province. The Red River Valley wil be spared, however we’ll be stuck under low clouds with a daytime high that struggles to make it to 10°C.

Tonight, a widespread frost potential exists over the most of Southern Manitoba. As a surface ridge moves into our area, winds will abate and we’ll see the cloud begin to break up a bit this evening. The greatest potential for frost looks to be over Southwestern Manitoba in the Virden, Melita, Pilot Mound & Brandon regions. Further east, here in the Red River Valley, some scattered clouds and a bit of moisture trapped in the valley should help temperatures stay above freezing, with overnight lows in the 2-3°C range. Areas outside the City of Winnipeg in the RRV certainly have a slight risk of a light frost. Winnipeg will likely be frost-free, with an off-chance of patchy frost in outlying areas near the Perimeter Highway.

Saturday will be our transition day with temperatures reaching 13-14°C and cloud streaming northwards from the Dakotas with the next incoming system. Rain will push up towards the International Border by morning, likely staying in the States but certainly poses the chance of a few showers along the border. The rain will stay near the border until Sunday, when the next big northward push arrives.

24. hour precipitation accumulation Saturday morning to Monday morning](https://img.skitch.com/20120525-mkq1sh9w3aa3twa7r6stuq9j2q.png)

Precipitation accumulation from the GEM-GLB model for Saturday morning to Monday morning. A broad swath of rain is forecast to fall from extreme SW Saskatchewan through Southern Manitoba.

And what a push it will be! Showers and thunderstorms will rapidly develop into an expansive area of rain on Saturday night, slowly pushing northwards across the Red River Valley. Most regions across Southern Manitoba should expect rain to start fairly early on Sunday and last through most of the day. Rain will likely taper off from west to east overnight, with only a few wrap-around showers moving across the RRV on Monday. It’s still early to give accurate estimates of rainfall totals for this next system, however in general, most regions across Southern Mantioba look to see at least 10-20mm of rainfall, with the potential for nearly 30mm in some areas of the RRV if some embedded convection can get going. Regions of Southwestern Manitoba that end up north/northwest of the main upper low track will see higher amounts as well, with 20-30mm of rain likely. This isn’t the best news for this year’s Teddy Bears Picnic, but hopefully shouldn’t dampen spirits too much at an event that has, historically, had to deal with some pretty awful weather. Wait, I’m getting deja vu…

Conditions look to improve through the middle of next week, with temperatures pushing back towards the 20°C mark and some sun finally making an appearance. That’s a ways to go, though, so grab your slippers and heat up some soup! We have some great stay-inside weather coming up. We’ll be sure to keep a close eye on this system and provide updates in the comments.

A Couple Unsettled Days, Then Warmer Weather Returns

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As we quickly approach the beginning of fall, Winnipeggers can be happy to know that after the next couple days, the mitts can go back into the closet.

So what’s on tap?  For this evening, most of the RRV should see heavy drizzle or light rain as a trough line moves through that connects two low pressure systems: one in central Saskatchewan and one in South Dakota.  The precipitation will move out overnight and tomorrow will bring mainly cloudy conditions with scattered drizzle and moderate northwest winds.  Showers or drizzle may make an appearance downwind of the lakes, but nothing widespread is expected.

On Wednesday afternoon into the overnight period, areas close to the International border may see some showers spread north from a system moving through the Dakotas, however it seems to me that the models are underestimating the effect of the ridge that will be positioned across the central Prairies.  It’s likely that the dry outflow from the ridge will keep things cloudy instead of rainy over southern areas of the RRV.

The rest of the week looks quite nice with sunny skies through much of the RRV and temperatures climbing into the high teens.  There’s definitely a chance that Winnipeg will see temperatures over 20°C, however I’d currently bet on just high teens as the models tend to over-amplify upper ridges in 60+ hour forecasts.  A string of disturbances will trek across the Dakotas, and there is a slight chance that some precipitation will nudge into areas near the international border, but for the most part, expect the second half of the week to be warm and dry.

As one other note, it looks that from here out, overnight lows look to be in the 5-10°C range, which is good news for farmers in the RRV, many of whom were able to escape the frost which affected Winnipeg and areas north and west on Saturday night.  Drier, frost-free conditions are sure to be good news for many of the province’s farmers.

Afternoon Showers & Cool Weather (and Frost!)

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Afternoon showers in the RRV with the slight chance of an isolated thunderstorm or two will mark the arrival of a much cooler arctic airmass in Southern Manitoba.

Under cloudy skies most of the day, the RRV will see increasing southerly winds today as a low pressure system approaches from Southern Saskatchewan.  As the low passes by this afternoon into the early evening, the RRV will see widespread showers with the slight chance of a thunderstorm.


Friday 21Z 3hr QPF w/MSLP Panel from GEM-REG 00Z Run

Current indications are that most of the RRV will see 5-10mm of rain.  There may be accumulations up to 15mm in a few isolated localities due to enhanced convection.  The rain will end by midnight with only a slight chance of a few hang-back showers in the cooler air.

The main story after that is that Winnipeg will be under a much cooler airmass.


Sat 00Z 850mb Temperature Panel from GEM-REG 00Z Run

With current 850mb temperatures hovering around 6°C, expect a chill in the air in the mornings over the weekend as the 850mb temperatures get down to the -2°C range.  This should translate to overnight lows of -3 to 0 through much of southern Manitoba over the weekend. 

Pick your tomatoes if you haven’t!  This weekend certainly holds the potential for widespread frost with the cooler air moving in over the Province. The areas most likely to see frost would be areas west of the RRV, and locales in the RRV north of Winnipeg, with patchy frost possible to the south and southeast of Winnipeg.